No abstract

A PSA value higher than 1.9 ng/ml determines a significant increase in the diagnostic yield. Adjuvant hormonotherapy has no influence on the PET results. FDG has a better correlation with the Gleason score than (11)C-choline.

We have investigated dual-time-point 18 F-FDG PET for the detection and delineation of high-grade brain tumors using quantitative criteria applied on a voxel basis. Methods: Twenty-five patients with suspected high-grade brain tumors and inconclusive MRI findings underwent 11 C-methionine PET and dual-time-point 18 F-FDG PET. Images from each subject were registered and spatially normalized. Parametric maps of standardized uptake value (SUV) and tumor-to-normal gray matter (TN) ratio for each PET image were obtained. Tumor diagnosis was evaluated according to 4 criteria comparing standard and delayed 18 F-FDG PET images: any SUV increase, SUV increase greater than 10%, any TN increase, and TN increase greater than 10%. Voxel-based analysis sensitivity was assessed using 11 C-methionine as a reference and compared with visual and volume-of-interest analysis for dual-timepoint PET images. Additionally, volumetric assessment of the tumor extent that fulfills each criterion was compared with the volume defined for 11 C-methionine PET. Results: The greatest sensitivity for tumor identification was obtained with any increase of TN ratio (100%), followed by a TN increase greater than 10% (96%), any SUV increase (80%), and an SUV increase greater than 10% (60%). These values were superior to visual analysis of standard 18 F-FDG (sensitivity, 40%) and delayed 18 F-FDG PET (sensitivity, 52%). Volume-of-interest analysis of dual-time-point PET reached a sensitivity of only 64% using the TN increase criterion. Regarding volumetry, voxel-based analysis with the TN ratio increase as a criterion, compared with 11 C-methionine PET, detected 55.4% of the tumor volume, with the other criteria detecting volumes lower than 20%. Nevertheless, volume detection presented great variability, being better for metastasis (78%) and glioblastomas (56%) than for anaplastic tumors (12%). A positive correlation was observed between the volume detected and the time of acquisition of the delayed PET image (r 5 0.66, P , 0.001), showing volumes greater than 75% when the delayed image was obtained at least 6 h after 18 F-FDG injection. Conclusion: Compared with standard 18 F-FDG PET studies, quantitative dual-time-point 18 F-FDG PET can improve sensitivity for the identification and volume delineation of high-grade brain tumors.

We evaluated the feasibility, safety, and efficacy of radioembolization (administered from one or two vascular points) after the redistribution of arterial blood flow in the liver in patients with hepatic neoplasms and arterial anatomic peculiarities (AAP). Twenty-four patients with liver neoplasms and AAP (graded according to Michel's classification) were included in the study. During pretreatment angiographic planning, all extrahepatic vessels that could feed the tumor were embolized and the intrahepatic vessels occluded in order to redistribute blood flow. The distribution of microspheres was initially assessed by using technetium-99m-labeled macroaggregated albumin ((99m)Tc-MAA) from one of two vascular points before the administration of yttrium-90 ((90)Y)-radiolabeled resin microspheres. Perfusion of lesions situated in the redistributed segments (L-RS) and nonredistributed segments (L-NRS) were compared by assessing the distribution of (99m)Tc-MAA by SPECT/CT. Perfusion was graded as normal, reduced, or absent. (90)Y resin microspheres were then injected from the same arterial sites as (99m)Tc-MAA and the tumor response recorded 3 months later. The tumor response in L-RS was compared with that in L-NRS and graded as better, similar, or worse. Among 11 patients with type I AAP in whom mainly vessels in segments I-III or IV were occluded, perfusion of L-RS was graded as similar (n = 7) or reduced (n = 4). Among the remaining 13 patients with AAP types III (n = 3), V (n = 4), VIII (n = 3), and others (n = 3) in which aberrant arteries were occluded, perfusion of L-RS was graded as similar (n = 9), reduced (n = 3), or absent (n = 1). Overall, (99m)Tc-MAA was present in the L-RS of 95.8% patients and the distribution of (99m)Tc-MAA in L-RS and L-NRS were graded as similar in 66.6% of patients. Compared with lesions in the L-NRS, tumor response in L-RS was similar in 23 cases and worse in 1 case. No complications were recorded after the administration of (90)Y resin microspheres. Redistribution of flow in L-RS is feasible and enables a safe and effective delivery of (90)Y resin microspheres that are able to be distributed via intrahepatic collaterals and access the microvasculature of L-RS.

FDG PET may detect recurrent ovarian cancer earlier than CIM, with higher sensitivity and even higher diagnostic accuracy.